The present invention relates, in general, to wind electric plants, and more particularly, to a wind electric plant of the type which includes a wind driven propeller or the like to drive an alternator for producing electrical energy.
U.S. Pat. No. 4,059,771 issued to Jacobs, et al. discloses a battery controlled variable speed alternator for wind electric operation. The present invention is an improvement of the just-mentioned Jacobs, et al. patent, and the disclosure thereof is fully incorporated herein by reference thereto.
In the referenced Jacobs, et al. patent, alternator output is controlled directly through controls responsive to alternator speed and battery voltage to provide a relatively constant excitation current for the field winding of the alternator from a storage battery, whereby the alternator field is fully excited at substantially all speeds of operation thereof. In the present improvement, alternator output is controlled through the field control of an exciter, such control enabling the alternator field to be fully energized even at slow speeds. Additionally, such control permits a fully energized degree of field saturation over the entire speed range.
The inventors have found that the field of wind electric plants has need of means for energizing the field of a slow moving alternator so that the alternator can develop full voltage at slow speed while also permitting speed increases or two or three times the starting speed. Such means should also permit full control of the energy output of the overall device. The presently disclosed device satisfies this need.